Towards the creation of a wine quality prediction index: Correlation of chardonnay juice and wine compositions from different regions and quality levels

Wine quality depends upon the composition of the grapes used in its production, which in turn depends on the weather and soil of the growing region together with viticultural practices. Region is used by many winemakers as a proxy for quality but objective quality measures are lacking. This study examined the compositional aspects of Chardonnay wines produced with berries from different regions. Through descriptive analysis, distinct sensory profiles were recognised for three diverse regions in South Australia (Adelaide Hills, Eden Valley, Riverland), which helped to pinpoint compounds relating to higher- and lower-quality Chardonnay wines. Correlations between the content of elements, fatty acids, free volatiles and conjugated glycosides in berries from different quality levels, and the composition of their corresponding wines, were investigated. Higher berry concentrations of linalool, (E)-linalool oxide, (Z)-3-hexen-1- ol, decanoic acid, vitispirane, Cu, Zn, and behenic acid, and lower °Brix and pH levels were related to higher quality wines.